Well cementing



E. V. CROWELL WELL CEMENTING Oct. 20, 1931.

Filed March 1, 1927 IN VEN TOR. 5'0 M Crows/1 R I b ATTORNEY.

Patented Oct. 20, 1931 PATENT; OFFICE ERD V. GBOWELL, F IDS ANGELES,CALIFORNIA.

WELL GEMENTING Application filed March 1,

This invention is an improvement in the method and apparatus forcementing wells disclosed in my co-pending applications, Ser. No. 5,477,filed January 29, 1925, and Ser. No. 121,040, filed July 7 1926; and itis the object of the present invention to provide for carrying ondrilling operations or circulating a washing medium through theunobstructed bore of a string of casing in a well, and then forcing acementing mixture downwardly through the casing to any predeterminedlevel and thence outwardly through ports in the casing to fill thesurrounding bore.

' In practice it has been found advantageous 1 to have the full bore ofa string of casing available when carrying on drilling operations orwashing down the string of casing, and it is also desirable whencirculating a washing medium preparatory to a cementing operation, toutilize the full bore of the easing and circulate the washing mediumdownwardly through the entire string of casing around its lower end andthence upwardly in the surrounding well bore.

i It is therefore theparticular object of the present invention toprovide a string of casing with an unobstructed bore and normally closedvalve controlled peripheral ports whereby the casing is adapted for flowof a 3m circulating medium downwardly through its unobstructed bore pastthe closed ports and around the lower end of the casing and thenceupwardly in the surrounding well bore, the casing being arranged toanchor a plug which is lowered in the casing in back of the washingmedium, with said plug anchored immediately below the peripheral portsso that a subsequently introduced cementing mixture is prevented fromflowing downwardly 40 through the casing below the plug and consequentlyforces open the normally closed valves controlling the ports to permitdischarge of the cementing mixture into the surrounding well bore.

It is a further object of the invention to employ a traveling plug inconjunction with the anchored plug, the traveling plug being forced'downthe well casing in back of the quantity of cement which is to bedischarged into the surrounding Well bore so as to force i\ 1927 s i I 8S U E a} enal No. 171,851.

the cement through the peripheral ports of the well casing; and thetraveling plug being arrested by seating on the anchored plug, indicatesthat all of the cement has been forced through the peripheral ports intothe surrounding bore and also closes the peripheral ports against backflow of the cement into the bore of the casing.

It is a still further object of the invention to provide the normallyclosed discharge ports in a fixed section of the string of casing whichmay be either an intermediate barrel section or a shoe at the lower endof the string, with said barrel or'shoe section forming the means forengaging the lower plug so as to 5 automatically anchor it in operativeposition.

The invention will be readily understood from the following descriptionof the accompanying drawings, in which: Jo

Fig. 1 is a vertical section through a well bore showing a string ofcasing, partly in axial section, constructed in accordance with theinvention and arranged for drilling operations or circulation of awashing medium prior to the cementing operation.

Fig. 2 is a similar view showing the lower plug anchored in the casingand the traveling plug co operating therewith during the cementingoperation.

Fig. 3 is a view similar to Fig. 2 but showing a modified constructionin which the invention is applicable to a casing shoe rather than anintermediate barrel section of the string.

Fig. 4 is a transverse section on the line 4-4 of Fig. 2. I

A usual string of easing A is received in the well bore 3, and the spacein the well bore surrounding the casing may have a washing 9 mediumcirculated therethrough and is ihen cemented oil to provide a standardwell construction. A fixed section of the string of easing, connectedthereto by psual threaded connections 1, may form either an intermediatebarrel 2 as shown in Figs. 1 and 2, or a shoe 2 at the lower end of thestring as shown in Fig. 3.

Thls'fixed section of the string of casing has an unobstructed bore 3forming a continuation of the uniform bore of the string, and peripheralports 4 open through the fixed section in spaced relation from its lowerend.

The ports 4 are normally closed by spring pressed valves 5 mounted ingrooves 6 1n the outer periphery of the ported section, but these valvesare adapted to open against the tension of their springs by increasedpressure 7 in the bore of the casing so as to permit passage of materialfrom the easing into the it is lowered through the bore of the casing tothe level of the recess.

In order to provide anchoring means for plug 10 in recess 7 the plug hasan intermediate reduced diameter 11 adapted to receive arcuate lockingslips 12 which are adapted to contract wholly within the outer peripheryof the plug. Bias springs 13 fixed to the plug in back of the slipsengage the latter so as to tend to expand the same beyond the peripheryof the plug; and expansion of the slips is preferably guided and limitedby abutments 14 on the plug engaging in notches 15 in the slips. As theplug is lowered through casing A the uniform bore of the lattercontracts the slips to permit free passage of the plug, and when theplug is opposite. recess 7 the annular enlargement formed therebypermits springs 13 to expand the slips so that they rest on shoulder 9and thereby anchor the plug.

Packing is preferably mounted on the plug to insure a tight shutting-offof the casing when the plug is anchored in recess 7 the parts being soarranged that when the plug is anchored its packing closes the bore ofthe casing just below ports 4. As a consequence a cementin'gimixtureintroduced into the well casing above the anchored plug is preventedfrom flowing down the casing past the plug and thereby forces valves 5open for disc arge of the cement through the ports 4 into thesurrounding well bore.

A predetermined supply of the cementing mixture is preferably thusdischar ed through ports 4, the quantity of cement leing measured by atraveling lug 16 lowered in the well casing in back of the cementingmixture. The traveling plug slides freely in the uniform bore of thecasing and is preferably provided with packing to prevent leakage of thecementin material past the plug.

The lower ends o plugs 10 and 16 are preferably tapered as shown at 17to guide the plu s through the bore of thecasing, and the pac g for theplugs may be mounted on annular shoulders 18 formed at the upper ends ofthe plugs by reducing their diameter as shown at 19. The packing ispreferably annular cup-packing 20 snugly engaging the casing wall andfixed against shoulders 18 by followers 21 which may be held in place bypins 22.

In operation the section of the string of casing which is provided withports 4 and recess 7, may form either an intermediate barrel 2 in thestring or a shoe 2 at the lower end of the string, depending uponwhether the well is to be cemented at an intermediate level or at theformation seat C.

The well casing thus presents a uniform unobstructed bore prior to thelowering of plug 10, with ports 4 closed by their spring seate valves 5.The casing may be washed down or drilling may be continued through thecasing with the unobstructed bore permitting freedom of such operations;and said washing operation may be by the various methods disclosed andclaimed in my co-pending applications Ser. No. 327,080, filed December19, 1928, and Ser No. 331,411, filed January 10, 1929. Thus for examplewhen it is desired to circulate a washing medium, the casing may restupon the formation seat so that the washing fluid forced downwardlythrough the casing will open valves 5 and thus flow outwardly throughthe valves and upwardly in the surrounding bore, or the casing may beelevated slightly from the formation seat so that the washing mediumwill flow downwardly through the unobstructed bore of the casing pastthe spring-closed valves 5 as shown in Fig. 1 and thence around thelower end of the casing and upwardly in the surrounding bore.

The washing medium may be forced downwardly through the casing by thelug 10 bein g lowered through the casing in back of the washing medium;the plug being preferably forceddownwardly by a cementing mixtureintroduced into the casing above the plug; and when the plug has beenlowered so that all ofthe washing fluid has been discharged and the plughas been automatically anchored in recess 7 immediately below ports 4 asshown in Fig. 2, the casing if it has been raised from the formationseat for circulattion around its lower end is again lowered to theformation seat when employing the shoe 2; or may be suspended at anydesired level with the well bore packed-off below barrel 2 by suitablepacking 30, which during the washingoperation remains in normalcontracted position as shown in Fig. 1 to permit passage of the washingmedium, but which when a cementing mlxture is discharged through ports 4is expanded by the weight of the cementing mixture so as to tightlyengage the well of the well bore and thereby pack-oil the bore inaccordance with usual practice.

The desired quantity of the cementing mixture is accurately measured bylowering the plug 16 into the casing in back of the predeterminedquantity of cement as shown in Fig. 2, the plug '16 being forceddownwardly against the cementing mixture by a suitable flow of water sothat the pressure opens valves 5 for discharge of the cementing materialthrough the ports 4 and into the surrounding-well bore above either theformation seat C or the packing 30, depending upon the use of eithershoe 2 or barrel 2.

When all of the cement is discharged, plug 16 is arrested by abutmentagainst anchored plug 10, thereby indicating that the cementingoperation is completed; and with the parts in this position the cementis prevented from back-flow into the casing, not only by the closing ofvalves 5, but also by the plug 16 closing the bore of the casing toports 4.

I have thus provided a construction which permits drilling operations orcirculation of a Washing medium through an unobstructed casing bore,with subsequent automatic anchoring of a plug in the bore, and flow ofcementing material downwardly through the casing until it is stopped bythe plug and thence outwardly through the casing to fill the surroundingwell bore.

I claim:

Well casing having an unobstructed open bore throughout its length, alateral port in the casing, the unobstructed open bore of the casingbeing recessed below the port with said recess forming a seat, a plugslidable in the bore of the casing and adapted for expansion in therecess to anchor the plug on the seat so as to shut-ofl' the entire boreof the casing below the port and leave the entire bore of the casingunobstructed above the port.

signature to this specification.

ERD Y. CROWELL.

In testimony whereof he has aflixed his

